P: Small and blurry previews before import

@Rikk Flohr: Photography Even if you couldn’t reproduce johnrellis’s recipe in the other thread, note that for the example posted by Millie25437294jyyx, in this thread both johnrellis and I both posted replies about finding the source of the unusually small preview used by the Import dialog box, using similar methods but independently. (Link to my reply)

I can reproduce the problem. I can add screen shots later, but just to get this information out, this is what I find with the sample file that was uploaded (short version: Something is weird with Lightroom Classic):

The magnification listed as 100% in the Lightroom Classic import dialog box is much smaller than expected, consistent with what the user reported. The Import preview is much smaller than the same 100% magnification after import as seen in Loupe or Develop. I also saw this same thing with a Canon R6 raw file I downloaded from a camera review website.

As usual, I started inspecting the raw image metadata using other applications.

In RawDigger, looking at the EXIF metadata, I can often find the exact size of an embedded preview, but none is found for the sample image, so I was puzzled by that. In the metadata, only the full raw image size and sensor size metadata are found, along with a mention of Canon Large (which the manual says is full size), so that all implies that the embedded preview is full size. In the Canon manual, I could not find a way to change the preview size in camera as the user said, so maybe those camera models just embed full size previews.

FastRawViewer lets you choose between displaying the raw image and the embedded JPEG image. Their sizes are only slightly different and, in agreement with RawDigger, appear to be full size.

In XnView MP, I finally found something different in its ExifTool view: A metadata section called QuickTime that includes an image size of 1624 x 1080. Hmm…

In GraphicConverter, in its ExifTool view I was also able to find that image size of 1624 x 1080, but there it was in a metadata section labeled Track 2.

So two applications were able to find an image size of 1624 x 1080 in that raw file. I took a screen shot of what 100% looks like in the Lightroom Classic Import dialog box, opened that in Photoshop, and measured that preview which Lightroom Classic Import claims to be 100%.

Lightroom Classic Import says 100% is 1624 x 1080.

And so what this research seems to indicate, is that for some reason, Lightroom Classic is pulling out a preview matching that small, hidden 1624 x 1080 image size, that most raw inspectors won’t even list, from a raw file that embeds a full size 6000 x 4000 preview.

My conclusion is that the user isn’t doing anything wrong, and Adobe needs to explain why the Lightroom Classic Import dialog box is showing that weird small 1624 x 1080 preview size that everybody else ignores, instead of the full size preview that other applications display and report in metadata.

Typically, when any software previews un-imported images, it’s displaying the preview embedded with the raw file, not actually rendering the raw file. One way of diagnosing this is to check how the same raw files preview in other applications, such as:

• In the macOS Finder, using the QuickLook feature (select an image and choose the command File > QuickLook, or press the spacebar). 
• In Apple Photos, when previewing to import. 
• In Adobe Bridge, browsing the card with the Embedded preview option. 
• In Adobe Bridge, browsing the card with the command File > Get Photos from Camera (similar to Lightroom Classic import). 

If you see the same low resolution previews in all applications by any company, then the cameras might be set to generate and embed raw previews at low resolution. You can then see if you can change the preview resolution setting in the cameras. 

If you see high resolution previews in Apple apps but low resolution previews in Adobe apps, then maybe there is a problem with Adobe preview support for later CR3 raw files. 

If you see high resolution previews in Apple apps and Adobe Bridge (with embedded previews), but low resolution previews in Lightroom Classic Import, then maybe there is a problem in Lightroom Classic import only.

Basically, inspect these raw file previews from different angles (without rendering the raw file!), so that you can then use process-of-elimination troubleshooting on the previews.

Are you connecting the camera to the computer with a USB cable or are you inserting the memory card into a card reader?